Independent wheel suspension



Oct. 20, 1942. A. w. KUMM INDEPENDENT WHEEL` SUSPENSION Filed Feb. 23, 1942 4 Sheets-Sheet l A. W. KUMM INDEPENDENT wHEEiI sUsKPENsIoN Oct, zo, 1942.

Filed Feb. 23, 1942 4 Sheets-Sheet 2 I Il wfllllllli NN, NN

m EN. m4 wm mm mm MN NN\ A Snoentor, ,4er/10e [f1/KUMM Bg I @JM/W Ctttorneg Oct. 2G, 1942. A, w, KUMM 2,299,241

INDEPENDENT WHEEL SUSPENSION Filed Feb. 23, 1942 4 Sheets-Sheet 3 i :inventor 64 65 `\\\\\\\z (Ittorrleg Oct. 20, 1942. A, w. KUMM INDEPENDENT WHEEL SUSPENSION Filed Feb. 25, 1942 l 4 Sheets-Sheet 4 K Snventor 1 w ,4er/10Q W KUMM Patented' O ct. gi), '1942 .UNITED sTATEs PATENT OFFICE 2,299,241 INDEPENDENT wnEEr. sUsrENsroN Arthur W. Kumm, Los Angeles, Calif.

Application February 23, 1942, Serial No.43l,930 s cnims. (ci. zat-sez) This invention relates to a novel form of independent suspension wheel assembly for vehicles and the like, and pertains particularly to a form of independent wheel assembly embodying supporting spring means positioned to act along a line transverse to the direction of movement of the axis of the suspended wheel member during operation thereof.

One of the particular objects of the inventionis Y to provide an independent wheel-supporting structure for vehicles and the like, in which supporting spring means are so linked with the Wheel as to secure a resultant spring action more comparable to that obtainable by a pneumatic cushion device, in that successive increments of deiiection of the wheel under load are opposed by progres- -sively increased restoring forces.

A further object of the invention is to provide an independent wheel-supporting structure in which supporting spring means are so linked with the wheel that the component ofvforce which is impressed upon the wheel is caused to be increased at a rate greater than the rate at which restoring forces are built up 1n the supporting spring means as a result of the deilection of the VWheel from its normal position under load.

vrespect to the frame of the vehicle, and spring means mounted on the frame and having a movable end portion linked to the axle member in such manner that an upward movement of the` axle member with respect to the frame member is opposed by the spring, the link means being so arranged that successive increments of upward movement of the axle member are caused to produce progressively increasing increments of the restoring force in the spring means. Theflink means are arranged in angular relation to the path of movement of the movable end portion of the spring means in order to eiIect this desired type of restoring-force augmentation, and the angular relation of the link means tosuch path tangent of` this angle.

between increases upon upward movement of the` wheel with respect to the frame under wheel loadin'gs in excess of normal. This change in the angular relation ci' the link means to the. direction in which the spring means are caused to build up the restoring forces also results in a change in the component o f such restoring forces which is directly realized at the wheel. More speciflcally, an annular relation is established such that the component of the spring restoring force which is applied at the wheel is a function of the The construction of this invention is illustrated in the accompanying drawings, in connection with the description of which the above and other features of the invention will be brought out. Referring to these-drawings:

^ Fig. 1 is a -front elevation of one embodiment, showing what would be the right front wheel of a conventional construction;

Fig. 2 is a plan view thereof; l

Fig. 3 is an enlarged vertical section, as taken on line 3-3 in Fig. 2:

Fig. 4 is'a'fragmentary detail corresponding to the lower right-hand portion of the construction of Fig'. 3, in which a modified ancillary construction has been embodied;

Fig. 5 is an enlarged transverse sectional detail, as taken on line 5 5 of Fig. 3;

Fig. 6 is a plan view of a modiiied form of the invention arranged to accommodate a drive axle, such as would be represented by the left rear wheel of an automobile or the like;

Fig. 7 is a rear elevation of the form shown in Fig. 6:

Fig. 8 is a transverse section as taken on line 8-8 in Fig. 7; and

Fig. 9 is a graphic representation of the angular relation which may be obtained between the various structural members of the construction under diilerent conditions, illustrating the magnitude of angular and dimensional changes obtained by the spring linkages.

Referring particularly to Figs. 1-3 and 5, a rigid frame member l, which may be considered as integral with the main frame structure of the vehicle, is provided in transverse relation to the longitudinal axis of the vehicle, said frame member I terminating at its outer ends in a yoke 2 carrying a rotatable kingpin-I journaled in bearings I. A steering arm I is connected to the lower end of the kingpin. 'I'he wheel axle, or spindle 6, is carried on a hub member or bushing 1, which is constrained to rotation: with the kingpin 3 in any ormovement is arranged so that the angle theresuitable manner which will allow axial Sliding movement therebetween, as through coacting splines or the like shown at 8.

Slidably mounted on the kingpin 3 I provide a crosshead member I provided with upper and lower bearing portions Illa and IIlb respectively engaging the upper and lower ends of the bushing l. The kingpin crosshead I0 is provided with inward extending bracket means IIlc and IIId to which a plurality of elongated link members II are pivotally attached as at I2. The link members I I are pivotally mounted at their inner ends to a guiding crosshead I3, as at I4, which crosshead I3 is slidably mounted on a guide bar I5 which extends transverse to the axis of the kingpin 3 and is secured at its outer end to the frame member I as at I6 and at its inner end to an-r auxiliary frame member Ia as at I'I, said auxiliary frame member Ia being rigidly secured to the frame member I in any suitable manner, as at I8. Bumper means of rubber or the like may be provided as at 2a to prevent upward movement of the crosshead III to an extent such that the enclosing "Sy1phon bellows (described below) would be crushed.

The supporting spring means for the vehicle wheel carried by the spindle 6 may comprise a compression spring 2I extending coaxially with the guide bar I 5, bearing at its outer end against the depending portion of the yoke 2 of the frame member l as at I6 and at its inner end against the outward directed face I3a of the 'guide crosshead I3. `In order to establish a high degree of rigidity in the structure I preferably employl two pairs of links I I, one pair at the forward side of the guide bar I5 and the other pair at the rearward side of said guide bar. The inward ends of links II of each pair may be attached to the crosshead I3 in symmetrical relation tp the path of movementv of the crosshead, as defined by the guide bar I5. I further preferably provide, for each of the links Il, an auxiliary link 22 pivotally connected to the mid-point of the link I I at its inner end 23 and pivotally con-V nected to the yoke 2 at its outer end. The links 22 are exactly one-half the length of the links II and the outer ends thereof 24 will be pivoted to the yoke 2. The pivotal attachment of the outer ends 24 of the links 22 will be established at the intersection of the planes of movement of the pivotal axes at points I2 and I4 in the respective pairs of links. More specically the planes of movement oi the pivot'points I2 are indicated by the dot-dash line P in Figs. 1 and 5 and the planes of movement of the respective pivotal axes of the pivot points I4 are indicated by the dot-dash lines p' and p" in Fig, 1. Owing to the rectilinear relations which are established by the links II and the half links 22, it will be appreciated that the axis of the guide bar I5 will have to be perpendicular to the axis of the kingpin 3, inasmuch as the pivot points I2 are constrainedV to movement in parallelism with the axis of the kingpin 3.

Upon upward movementof the spindle 6 and the bushing 8 along the kingpin 3 y(as would be occasioned `by the vehicle striking a bump in the road) the ykingpin crosshead IIJ will be moved upwardv therewith.l ,Upward movement of the crosshead III will. through the links II, cause an inward movement of the crosshead I3, which movement is opposed by the compression spring In this. construction the kingpin 3 and the bushing or hub member I constitute cooperating guide means for the spindle 6 in its upward in the cosine of this angle.

and jdownward movement with respect to the frame members I, which movement is communicated to the crosshead `I3 through the crosshead III and the links II.

By virtue of the angular relationship established between the path of movement of the free end of the spring 2I (along the guide bar I5) and the links II, the resultant outward movement of the guide crosshead I3 will increase rapidly with successive increments. of deflection of the wheel spindle 6 under load. The type of Inovement obtained will be appreciated when it is realized that the vertical movement of the kingpin crosshead III corresponds to .changes in the sine of the angle between the link II and the bar I5.v while the transverse' movement of the free end of the spring 2I corresponds to changes The character of this movement is diagrammatically'illustrated in Fig. 9 in which the line A-B corresponds to the line of movement of a pivot I4 and the line A-As corresponds to the line of movement of the corresponding pivot point I2 of a particular length link II. The scale of Fig. 9 is so selected that when progressive one inch de ections of the wheel axis (as defined by the spindle 6) are plotted at A1, A2, As, A4, and As, the respective corresponding positions of the pivot point I4y at the inner end of the link will be such as are indicated jat B1, Bz, B3, B4, and B5 for a link of twelve inches in length, the point B indicating the position of the pivot I4 when the pivot point I2 at the outer end of the link II is aligned with the pivot point 24 at the outer end of the link 22, as at the point A. Corresponding positions where a link II of ten inches in length is employed are` shown at C1, C2, Cs, C4, C5, and C. Taking a twelve-inch link, for example, it will be noted that the outward movement of the inner end of the link II through positions B-B5, in response to the upward deections indicated from A to A5, increases progressively, each increment of movement being greaterthan the preceding increment. The restoring force which would be built up in a spring member at the inner end of the link II- would,y according to Hookes Law, be directly proportional to the indicated displacements. At the .same time the component of downward force at the outer end of the link II will be a function of the angle between the link and the base line A-B which is referred to as 0 in the accompanyingtable. This function is that of the tangent of this angle, and it will be appreciated that the reend of the link II may be expressedby the following equation, F= tan 0 [(kD) -l-Ll, where 1c iS the constant of the spring, D is the deection of the free end of the spring measured by the outward movement of the inner end of the link, and L is the restoring force which is exerted by the spring when the inner end of the link II is at its maximum inward opsition, i. e., the preloading of the spring. Y

In Fig. 9 I have also illustrated the respective positions of the half link 22 in connection with the twelve-inch length link II at various angles of inclination of said link II.

The following table illustrates the various downward forces (termed wheel loading) .in a suitable iiexible envelope, or the like.

' length, a value of 3,500 pounds for L, and for the ten-inch length, values of 2,500 pounds and 3,500

hicle constructions, as at 00. In line with the respective frame members li and 0,2, and at each end thereof, I provide a pair of vertical guide bars 30 and 00, upon which a vertically slidable cross'head member il is slidably mounted;

pounds for L. "Sylphon bellows are preferably provided to en- 2000d/iuch spring factor Link length eliieeegtlxls l a Tan 9 Springixupres- Spring loading Wheel 2500# m5 loading preload prelcad Inches Inches Inches Pounds Pou/nds 12 A-B) e-B-A 0.00 0. 00 3,500 00 l2 Ai-Bl) l. (fi-A1) A-Br-Ai 0. 0838 0. 08 (B-Bx) 3,020 315 l2 Aa-Bg) 2 (A-Az) A--Bg--i` 3 0. 1694 0. 19 (B-B=) 3,800 656 12 Aar-Bi) Ble-A1) A-BAa 0.2588 v 04103-333) 4,320 l, 118 12 (At-B4) 4 A- A AB4A5 0. 3550 0. 73 B-B 4,060 1,760 l2 (Ay-Br) 5 (ei-dir) A-Bxs-As 0.4005 l. 14 B-Bs) 5,780 2, 600

(A C) 0 A-C-A 0.000 0.000 2, 500 000 l0 (A1-C1) l (A-AO A-C1-A1 0. 1008 0.08 G-C 2, 050 282 10 (A3-C2) 2 (A-Ai) A-Cr-Az 0.2047 0.23 COi) 2, 000 606 10 Aly-C3) 3 (A-A A-Ca--As 0.3151 0.48 (C-Ca) 3,480 1,090 10 Ai-Ci) 4 (A-A) AC4A4 0. 4386 0.88 (C-CD 4,200 1,868 10 Arr-Cs) 5 (A-As) AC5A5 0.5807 1.39 (C-Cs) 5, 280 3,060 1o (A-C) o A-o-A l 0.000 0. 000 3, 500 000 l0 (A1-C1) l (A-Al) A--Ci-Ai 0.1008 0.08 (C-CD 3, 660 383 10 (Az-Ca) 2 (A--A A-Cn-a 0. 2047 0. 23 (C-Cz) 3, Q60 811 l0 (Aa-Ci) 3 (A-Aa) A-C;A3 0.3151 0. 4B (C-C) 4, 460 1,405 10 (Ar-C4) 4 (A-A4) A-Ci-Al 0.4386 0.88 (i3-C4) 5, 260 2, 307 10 (A5-Cr) 5 (1i-A5) A-C-As 0.5807 1.39 (C-Cr) 6, 280 3, 647

In order that the various sliding parts may close the otherwise exposed portions of the bars be suitably lubricated and that dirt and ,grit may be excluded, I preferably enclose the same example, I have illustrated the use of Sylphon bellows as at 3l and 32 above and below the crosshead it which enclose the kingpin 3, and as at 33 and 34 inward and outward of the crosshead i3, which enclose the guide bar i5. A suitable passage as at 35 may be provided in the kingpin 3, for transfer of uid lubricant between the rbellows 3i and 32 upon vertical movement of the crosshead i0 along the lringpin 3. The spaces 33 and 3ft within the respective bellows 33 and 34 may be filled with a fluid lubricant and utilized as a "shock absorber or,4 more properly, a snubber which will opposel For the inward or "return travel of the crosshead i3, if desired. As shown in Fig. 3, the crosshead i3 may to this end be provided with check valve means 36.2.dapted to permit substantially free passage of iiuid rom space 33' to space 34', together with an adjustable needle valve 37 or the like to restrict the return iiow from space 34 to space 33.

Where the operating iluid pressures are of suchvalue as to exceed the safe operating limits of a "Sylphon bellows, I may employ a more sturdy snubber construction, as by means of a cylinder member 38 secured -to or :forming4 a part of the frame member la, and a cooperating piston member 39 secured to or forming a part of the crosshead I3, as shown in Fig. 4. Valve means 36 and V3l will be provided to control the flow of uid.

In Figs. 6, 7, and 8 I have shown an adaptation of the construction to a non-dirigible drive construction. In this construction two generally parallel transverse -frame members 4I and 42 are provided, which are maintainedin spaced relation in the direction ofA the travel of the vehicle through the agency of a brace member 43 at each end. The frame members Il and 42 may be Aconnected together rigidly at their center.portions through the agency of the 'diferential customarily employed in automotive vedie is connected to the drive member of thedifferential through apair of universale 53 and a shaft member dil.

The spring'suspension may comprise two elongated spring members 55 and 5t, which preferably extend substantially in the planes defined by the respective frame members il and 02, and are buttressed at their outer ends against vertical e portions #li and 112' of such frame members. The inner ends of the spring members 55 and 55 are engaged by a guide crosshead 5l, slidably mounted on guide' bars 53 and 59 corresponding in function to the guide bar I5 above. The crosshead M is linked to the crosshead 5l through the agency of link mem'- bers 0i and 02, corresponding in function to the linkmembers il and 22 above, said link members Si being pivotally mounted as at 63' at their outer ends to the crosshead 4l, as through projecting arm porti-ons 07a thereof, and at their inner ends to the crossheacl 51 as vat. 64. The link members $2 are pivotally secured at their outer ends to the respective frame portions 4| and 42', as at 65, and to the mid-point of the length of the associated links 5 I' as at 66. Enclosures for the guide bars 58 and 59 may be provided, as at 51 and 68, corresponding in function to the members 33 and 34 above.

In this construction the guide bars 45-46 and the crosshead 41 constitute the cooperating guide means for the vertical movement of the axle 52, corresponding to the function of .the members 3 and l0 above. Y

The disclosed invention will be subject to mod-A ication dictated or engendered by he specific use to which the construction is put in practice.

it will be appreciated that where half links such as 22 and 62 are employed, it will be necessary to provide an inclination of the guide means for the crosshead I3 or 51 so that the required rectilinear relation between the respective crossheads is preserved. Where the construction is such as to dispense with the use of the half links, this rectilinear relation is not required, and an eiiective increase in the angle may be obtained l by an initial inclination of the path of movement of the spring crosshead with respect to that of the kingpin crosshead. y

I claim:

l. A wheel assembly for vehicles and the like, which comprises: a frame member; an axle member adapted to carry a vehicle wheel; coomrating guide means on said frame member and said axle member, said'guide means comprising two relatively movable guide members adapted for linear sliding relative movement along a generally vertical axis, one of said guide members being constrained to vertical movement with said axle member and the other being secured to said frame member; an elongated spring member having a fixed end engaging said frame member and a 4free end operatively associated with said axle member; elongated link means pivotally connected at one end to said one guidemember and pivotally connected at the other end to the free end of said spring member to provide the operative association thereof with said axle member, said link means vbeing normally inclined downward from said one end to said other end, and said spring member biasing said one guide member and said axle member downward at all positions of normal relative movement of said guide members; and guide means-mounted on said frame member and engaging the free end of said spring member to guidethe same along a pathA extending transverse to said axis and at an acute angle with respect to the length of said linear sliding relative movement along a gener-` ally vertical axis, one of said guide members being constrained to vertical movement with said axle member and thel other being secured to said frame member; an elongated spring member having a fixed end engaging said frame member and a free end operativelyassociated with said one guide member and said axle member; elongated link means pivotallyl connected at one end to said one guide member' and -pivotally connected at the other end to the free e'nd of said spring member to provide the operative association thereof with said axle member, said link means being normally inclined downward from said one end to said other end, and said spring member biasing said one guide member and said axle member downward at all positions of normal relative movement of said guide members; additional elongated link means pivotally connected at one end to the mid-point of said first-named link means and pivotally connected at the other end link means at all positions of normal relative movement of said guide members.

2. A wheel assembly for vehicles and the like, which comprises: a frame member; an axle member adapted to carry a vehicle wheel; kingpin means rotatably mounted on said frame member; a guide member'secured to said axle member and slidingly mounted on said kingpin means for movement along a generally vertical axis and constrained to rotation therewith; an

elongated spring member having a iixed end engaging said frame member and a free end operatively associated with said guide member;

elongated link means pivotally connected at one member downward at all positions of normalsliding movement of said guide member on said kingpin member; and guide means mounted on said frame member and engaging the free end of said spring member to guide the same along a path extending transverse to said axis and at y an acute angle with respect to the length of said link means at all normal positions ofsaid guide member with respect to said kngpin means.

3. A wheel assembly for vehicles and the-like, which comprises: a frame member; an axle member adapted to carry a vehicle wheel; cooperating guide means on said frame member and said to said frame means; and guide means mounted on said frame member and engaging the free end of said spring member to guide the same along a path extending transverse to said axis and at an acute angle with respect-to the length of said link -means at all positions of normal relative movement of said gide members, the pivotal connection of said additional link means to said frame means being established at the intersection of said path with the path of movement of the pivotal connection of'said one end of said first-named link means, and .said two paths of movement extending perpendicular to each other.

4. A wheel assembly for vehicles and the like, which comprises: a frame meniber; 'an axle member adapted to carry avehicle wheel; cooperating guide means on said frame niember'and said axle member, said guide' means coinprisihg two relatively movable guide members adapted for linear sliding relative movement along a generally vertical axis, one of said guide-members being constrained to vertical movement with said axle member and the other being s'ecured to said frame member; an elongated spring member having a ixed end engaging said frame member and a free end operatively associated with said one guide member and said axle member; a pair of elongated link means at each side of said spring ber, each of said links being normally inclined downward from said one end to said other end, and said spring member biasing said one guide member and said axle member downward at all positions of normal relative movement of said guide members; and guide means mounted on said frame member and engaging the free end of said spring member to guide the same along a path extending transverse to said axis and at an acute angle with respect to the length of said link means at all positions of normal relative movement of said guide members.

5. The construction set forth in claim 4, said other guide means comprising a kingpin member rotatably mounted on said frame member, and said one guide means comprising a bushing member carrying said axle member and slidably mounted on said kingpin for rotation therewith, and a bracket member constrained to vertical sliding movement with said bushing member on said kingpin member but in freerotative engagement with said kingpin member, the said one ends of said links being pivotally secured to said bracket member.

6. A wheel assembly for vehicles and the like, which comprises: a frame member; an axle member adapted to carry a' vehicle wheel; cooperating guide means on said frame member and said axle member, said guide means comprising two relatively movable guide members adapted for linear sliding relative movement along a generally vertical axis, one of said guide members being constrained to vertical move-` ment withl said axle member and the other being secured to said frame member; an elongated spring member having a iixed end engaging said frame member and a free end operatively associated with said one guide member and said axle member; 'a pair of elongated link means at each side of said spring member, each link of each pair being pivotally connected at one end to said one guide member and pivotally connected at the other end to the free end of said spring member to provide the operative association thereof with said axle member, each of said links being normally inclined downward from said one end to said other end, and said spring member biasing said one guide member and said axle mem-A ber downward at all positions of normal relative movement, of said guide members; additional elongated link means pivotally connected at one end to the mid-point of said first-named link means and pivotally connected at the other end to said frame means; and guide means mounted on said frame member and engaging the free end of.said spring member to guidethe same along a path extending transverse to saidf axis and at an acute angle with respect to the length of said link means at all positions of normal relative movement of said guide members, the pivotal connection of said additional link means to said frame means being established at the intersection of said path with the path of movement of the pivotal connection of said one end oi' said-rst-named link means, and said two paths of movement extending perpendicular to each other.

'7. The construction set forth in claim 6, said other guide means comprising a kingpin memi ber rotatably mounted on said frame member,

and said one guide means comprising a bushing member carrying said axle member and slidably mounted on said kingpin for rotation therewith, and a bracket member constrained to vertical sliding movement with said bushing member on said kingpin member but in free rotative engagementv with said kingpinmember, the said one ends of said links being pivotally secured to said bracket member.

8. A Wheelv assembly for vehicles and the like, which comprises: a frame -member; an axle member adapted to carry a vehicle wheel; cooperating guide means on said frame member and said axle member, said guide means comprising 'two relatively fixed spaced guide members disposed at opposite sides of said axle mem-1 ber and a relatively movable guide member secured to said axle member and adapted for sliding movement with respect to said first-named guide members along a generally vertical axis; two elongated spring members, each having a xed end engaging said frame vmember adjacent one of said relatively fixed guide members and a free end operatively associated with said relatively movable guide member, said spring members extending generally parallel to said axle member; elongated link means pivotally connected at one end to said relatively movable guide member and pivotally connected at the guide means mounted on said frame' members and engaging the free ends of said spring members to guide the same along respective paths.

each extending transverse to said axis.

' ARTHUR W. KUMM. 

